Courtesy:Prof Nabil Ebraheim, University of Toledo, Ohio, USA

Adamantinoma: Key Features and Management

Overview

• Adamantinoma is a rare, low grade malignant bone tumor that most often affects young adults.
• It commonly involves the tibia, particularly the diaphysis.

Clinical Features

• Patients typically present with long standing pain.
• Localized tenderness over the tibia may be present.
• A palpable mass or anterior bowing of the tibia may be noted.

Radiological Features

• Radiographs often show multiple lucent and sclerotic lesions producing a bubble like appearance.
• The lesion usually occurs in the diaphysis of the tibia.
• Periosteal reaction is typically absent.

Pathology

• The tumor is biphasic, composed of epithelial cell nests within a fibrous stroma.
• Immunohistochemistry typically shows keratin positivity.

Differential Diagnosis

• Chondromyxoid fibroma.
• Fibrous dysplasia.
• Osteofibrous dysplasia, which occurs in children and is benign.

Related Conditions

• Osteofibrous dysplasia may resemble adamantinoma radiologically.
• Unlike adamantinoma, osteofibrous dysplasia shows osteoblastic rimming and is managed conservatively.

Management

• Treatment involves wide surgical excision with reconstruction.
• Chemotherapy and radiation therapy are generally not effective for low grade malignant bone tumors such as adamantinoma.
• Similar surgical management applies to parosteal osteosarcoma and chondrosarcoma.

Metastasis and Follow Up

• Pulmonary metastasis may occur in approximately twenty five percent of cases.
• Long term follow up is required due to the risk of recurrence and metastasis.

Summary

• Adamantinoma is a rare tibial tumor with characteristic clinical, radiological, and pathological features.
• Wide resection remains the primary treatment approach.